Endotracheal intubation procedures are performed on certain medical patients. For example, a tube providing an airway may be introduced to assist the breathing of a patient having undergone certain kinds of trauma. The arcuate shape of a conventionally formed oral cavity and upper throat area of a human is known. Various devices are also known, having a cooperating arcuate shape, effective to assist in introducing a tube, or other medical device, through the mouth and into the throat of a patient.
One device effective to assist in introducing an endotracheal tube includes an arcuate-shaped laryngoscope blade. Such a blade typically is formed from metal, or a very stiff plastic-like material, and has a spatulate, axially curved shape formed to cooperate with the conventional shape of oral cavity structure. The curved spatula portion of the blade is used for retracting soft tissue and opening the patient's jaw and mouth to form a clear, open path through which a tube or instrument may be inserted. In general, a laryngoscope blade is transversely very stiff to permit its use as a retractor for soft and hard tissue, while resisting significant bending deflection of the curved portion of the blade. Significant bending deflection of the curved portion under a working load would undesirably place the proximal handle associated with the blade into a blocking position and thereby interfere with creating the desired clear passage through which installation of a tube may be visualized.
In those cases where the patient is unconscious, there is no patient gag reflex over which the medical practitioner must surmount to install a tube, or to insert some other medical device. Consequently, difficulty of an intubation procedure is greatly reduced, although not eliminated. However, there exist instances where the patient is awake, at least partially alert, desirably remains in such condition for a further period of time, and prompt intubation must be effected in spite of such facts. In such cases, the patient's own gag reflex can constitute a significant obstacle to intubation.
Awake endotracheal intubations are typically accomplished using a fiber optic guide, and require anesthetizing the oral cavity, oropharynx, tonsillar pillars, base of the tongue, supragottic region and vocal cords, and other deep pharyngeal structure, such as the deep posterior pharyngeal wall, pyriform fossa on either side of the larynx, vallecula, and on to the proximal trachea. Anesthetization typically starts with topical application of anesthetic fluid at the front of the oral cavity, and then progresses inward toward the tracheal-esophageal bifurcation area. Typically, an area will be numbed prior to moving on to the next deeper area. Unfortunately for the patient, each new area receiving anesthetic initially presents a new stimulated area to promote a gag reflex.
It is generally desirable to apply anesthetic agent in a substantially uniform coating to reduce waste and avoid over-, or under-, medication. Application of anesthetic topically by way of a transfer medium, such as a sponge, often produces a substantially non-uniform coating of agent on the patient's tissue, as well as physically imposing on non-anesthetized areas. Squirting anesthetic agent from the nozzle of a syringe, e.g., as a jet, is equally unsatisfactory, and also wasteful. Known misting nozzle arrangements are not satisfactory to apply anesthetic agent in all desired areas for an endotracheal intubation procedure.